Amino boronic acids and related compounds and derivatives will be synthesized as analogues of naturally occurring amino acids and peptides. It is anticipated that some of these will bind to enzymes with consequent inhibition of enzyme activity. Possible practical applications may include use as probes for mechanisms of enzyme action, and perhaps useful anticancer or antibiotic agents may be found. Our recently discovered synthesis of alpha-chloro boronic esters will be used to provide precursors to the boron analogues of the twenty naturally occurring amino acids, which should result upon treatment of the corresponding chloro compounds with ammonia or ammonia synthons. The synthesis of the alpha-chloro boronic esters is readily modifiable to provide optical resolution and probably stereoselective synthesis of the desired enantiomer to match the naturally occurring amino acid or peptide analogue. Amido boronic acids may be obtained by N-acylation of the amino boronic acids or their esters. It is expected that peptide analogues having a boronic acid function in place of the carboxyl terminal group can be synthesized, and representative examples will be chosen.